IEC IEC61156-12 Edition 2.02025-04 REDLINE VERSION INTERNATIONAL STANDARD Multicore and symmetrical pairlquad cables for digital communications - Part 12: Symmetrical single pair cables with transmission characteristics up to 600 MHz 1,25 GHz-Work area wiring-Sectional specification IEC 61156-12:2025-04 RLV(en) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright @ 2025 IEC, Geneva, Switzerland or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IEC's member National Committee in the country of the requester. if you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication, piease contact the address below or yourlocal IEC memberNational Committeeforfurther information IEC Secretariat Tel.:+41229190211 3, rue de Varembé [email protected] CH-1211 Geneva 20 www.iec.ch Switzerland About the IEC International Standards for all electrical, electronic and related technologies. About IEC publications The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the latest edition, a corrigendum or an amendment might have been published IEc publications search - webstore.iec.ch/advsearchform IEc Products & Services Portal -products.iec.ch The advanced search enables to find IEC publications by a varietyofcriteria(reference number, text, technical publications previews, graphical symbols and the glossary. committee, ...). It also gives information on projects, replaced With a subscription you wili always have access to up to date and withdrawn publications. content tailored to your needs. IEc Just Published - webstore.iec.ch/justpublished Electropedia-www.electropedia.org Stay up to date on all new IEC publications. Just Published The world's leading online dictionary on electrotechnology, details all newpublications released.Available online and once containing more than 22 500 terminological entries in English a month by email. and French, with equivalent terms in 25 additional languages. Also known as the International Electrotechnical Vocabulary IECCustomerServiceCentre-webstore.iec.ch/csc (IEV) online. If you wish to give us yourfeedback on this publication or need furtherassistance, please contactthe Customer Service Centre: [email protected]. IEC IEC 61156-12 Edition 2.0 2025-04 REDLINEVERSION NTERNATIONAL STANDARD Multicore and symmetrical pair/quad cables for digital communications - Part 12: Symmetrical single pair cables with transmission characteristics up to 600 MHz 1,25 GHz - Work area wiring - Sectional specification INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS33.120.20 ISBN 978-2-8327-0407-3 Warning! Make sure that you obtained this publication from an authorized distributor. IEC61156-12:2025RLVIEC2025 CONTENTS FOREWORD. 4 1 Scope .6 2 Normative references . 3 Terms and definitions 4 Installation considerations 4.1 General remarks. 4.2 Bending radius of installed cable 4.3 Climatic conditions. 5 Materials and cable construction 5.1 General remarks 5.2 Cable construction .8 5.3 Conductor .8 5.4 Insulation. 5.5 Cable element. .8 5.6 Screening of the cable element .8 5.7 Cable make-up .8 5.8 Screening of the cable core 5.9 Sheath.... 5.10 Identification 5.11 Finished cable . ..9 6 Characteristics and requirements .9 6.1 General remarks ..... 9 6.2 Electrical characteristics and tests. 10 6.2.1 Conductorresistance .10 6.2.2 Resistance unbalance 10 6.2.3 Dielectric strength.. 10 6.2.4 Insulation resistance... 10 6.2.5 Mutual capacitance... 10 6.2.6 Capacitance unbalance 10 6.2.7 Transfer impedance...... 10 6.2.8 Coupling attenuation and low frequency coupling attenuation. 11 6.2.9 Current-carrying capacity.... .12 6.3 Transmission characteristics... .12 6.3.1 Velocity of propagation (phase velocity).. .12 6.3.2 Phase delay and differential delay (delay skew).... 6.3.3 Attenuation (a).... 13 6.3.4 Unbaiance attenuation (TCL and EL TCTL) .13 6.3.5 Alien (e